BELFAST, Northern Ireland — President Biden said Wednesday that Northern Ireland must “not go back” to the violence that scarred it for years before a U.S.-brokered peace deal 25 years ago, nudging politicians to resolve a political crisis that has left this part of the United Kingdom without a functioning government.

President Biden delivers his keynote speech at Ulster University in Belfast, Northern Ireland, on Wednesday. Aaron Chown/PA via AP

Speaking of the economic growth Northern Ireland has experienced since the Good Friday Agreement ended 30 years of sectarian bloodshed, Biden said: “It’s up to us to keep this going.”

On his first presidential visit to Northern Ireland, Biden dangled the prospect of more American investment to help fuel economic growth – especially if Belfast’s fractious politicians resolve a stalemate that has put their government on pause.

“The simple truth is that peace and economic opportunity go together,” Biden said during a speech at Ulster University’s new campus in Belfast. He said the glass-clad downtown building would have been unthinkable during the years of bombings and shootings known as “The Troubles.”

“Where barbed wire once sliced up the city, today we find a cathedral of learning, built of glass,” he said.

Noting that Northern Ireland’s total economic output had doubled in the quarter-century since the Good Friday peace deal was signed in April 1998, Biden urged people in Northern Ireland to “sustain the peace, unleash this incredible economic opportunity, which is just beginning.”

Biden urged all political parties to get back to work, saying “democracy needs champions” and that Northern Ireland’s future is in their hands.

“I hope the assembly and the executive will soon be restored,” he said. “That’s a judgement for you to make, not me, but I hope it happens.”

Biden’s visit was timed to mark the anniversary of the Good Friday accord, which the U.S. was key to striking. Biden credited people who were willing to “risk boldly for the future” by reaching the agreement, reminding the audience that “peace was not inevitable.”

Referring to a February gun attack on a senior police officer – blamed by authorities on Irish Republican Army dissidents opposed to the peace process – Biden said “the enemies of peace will not prevail. Northern Ireland will not go back, pray God.”

While peace has endured, Northern Ireland has been without a functioning government since the Democratic Unionist Party, which formed half of a power-sharing government, walked out a year ago over a post-Brexit trade dispute.

Biden met briefly before his speech with the leaders of the DUP and Northern Ireland’s four other main political parties.

Biden has faced mistrust from pro-British unionists because of his Irish American heritage. Sammy Wilson, a DUP lawmaker in the U.K. Parliament, told Talk TV that Biden “has got a record of being pro-republican, anti-unionist, anti-British” – a claim the White House firmly denied.

Biden’s speech carefully navigated Northern Ireland’s complex political currents, referring to both his British and his Irish ancestry, and noting the contribution to the U.S. of largely Protestant Ulster Scots as well as Irish Catholics like his own forebears.

Such things don’t go unnoticed in Northern Ireland. DUP leader Jeffrey Donaldson said Biden’s “reference also to his own British ancestry I think indicates hopefully that we have a president that recognizes the United Kingdom is a close ally and friend of the United States.”

But Donaldson doubted whether the president’s visit would “change the political dynamic.”

“I am clear what needs to happen to make the progress that we all desire – and that is that Northern Ireland’s place within the United Kingdom is both respected and protected, and we want to see that in law,” he said.

Michelle O’Neill from Irish nationalist party Sinn Fein said Biden had “sent a clear message to the DUP” about the need to get back to work.

Biden also had tea with U.K. Prime Minister Rishi Sunak during his Belfast stopover. The president spent less than 24 hours in Northern Ireland before moving on to the Republic of Ireland to begin a three-day visit, scheduled to include an address to the Dublin parliament, attendance at a gala dinner and trips to two ancestral hometowns.

U.K. officials denied that the brevity of the visit amounted to a snub. Sunak said he and Biden had a “very good discussion” about investment in Northern Ireland, along with foreign policy issues.

“We’re very close partners and allies. We cooperate on a range of things,” Sunak said.

Northern Ireland’s political crisis stems, in part, from Brexit. Britain’s departure from the European Union left Northern Ireland poised uneasily between the rest of the U.K. and EU member Ireland and put the peace agreement under increased strain.

After much wrangling, Britain and the EU struck a deal in February to address the tensions over trade, eliminating many of the customs checks that had irked businesses and angered unionists. The Democratic Unionist Party, though, says the agreement doesn’t go far enough to address concerns about Northern Ireland’s place in the U.K., and has refused to return to government.

Biden, who has urged Britain and the bloc to put Brexit squabbling behind them, praised U.K. and EU leaders for trying to sort out the “complex challenges” created by Brexit.

Neil Given, a civil servant who lives in Belfast, welcomed Biden’s visit but said his “expectations are not great” that it would unblock the political logjam.

“We have prevaricated for well over a year now, and ever since the signing of the Good Friday Agreement there have been numerous stoppages of the institutions of Stormont,” he said. “Whether or not Mr. Biden’s visit can in 24, 48 hours pull people together and perhaps get a message we really do need to get back to government, I don’t know.

“But hopefully he can do that. I know there is no more powerful person certainly to be over that can give out that message.”